Electrohydraulic control apparatus for consumer valves

ABSTRACT

The apparatus comprises an operation control unit, and a plurality of consumer control units with consumer conduits for a plurality of hydraulic motors. The consumer conduits are individually controlled by spring-biased consumer valves which are, respectively, actuated under control of single-stroke electromagnets. The operation control units include a springbiased control valve actuated by another single-stroke electromagnet to connect inlet means and outlet means, respectively, through a connecting conduit with all consumer control units.

United States Patent Heinz Flaschar Asperg;

Klaus Schneider, Ludwigsburg; Heinz Klelnschmidt, Stuttgart-Wangen, all of Germany Sept. 16, 1970 Dec. 7, 1971 Robert Bosch Gmbl-l Stuttgart, Germany Sept. 23, 1969 Germany [72] Inventors Appl. No. Filed Patented Assignee Priority ELECTROHYDRAULIC CONTROL APPARATUS FOR CONSUMER VALVES 14 Claims, 2 Drawing Figs.

U.S. Cl ..l37/596.12, l37/27.l2, l37/625.64, l37/596.l6, l37/625.64, 137/60 [51] lint. Cll ..Fl6k 11/00, Fl6k 11/00 [50] Fielldol'Search 137/271,

[56] References Cited UNITED STATES PATENTS 2,98 l ,287 4/1961 Caslow l37/625.64

Primary Examiner-Henry T. Klinksiek AuorneyMichael S. Striker ABSTRACT: The apparatuscomprises an operation control unit, and a plurality of consumer control units with consumer conduits for a plurality of hydraulic motors. The consumer conduits are individually controlled by spring-biased consumer valves which are, respectively. actuated under control of single-stroke electromagnets. The operation control units include a spring-biased control valve actuated by another single-stroke electromagnet to connect inlet means and outlet means, respectively, through a connecting conduit with all consumer control units.

BACKGROUND OF THE INVENTION The present invention relates to control apparatus for controlling the flow of fluid to and from hydraulic consumers, such as hydraulic motors.

The US. Pat. No. 2,981,287 discloses an electrohydraulic control apparatus for a hydraulic consumer apparatus which is capable of holding, lifting and lowering an object. For controlling several hydraulic consumer motors, consumer valves are used each of which is operated by two electromagnets. Such magnets are not only expensive, but also take up space, and the high weight of the structure is undesirable if the apparatus is moved.

The US. Pat. No. 2,916,051 also discloses control apparatus for a hydraulic consumer motor which is capable of performing only two functions, namely lifting and lowering, while holding the object is not possible.

The German Pat. No. 1,039,364 also discloses control apparatus for several consumer motors in which manually operated control slides are associated with means which close the inlet for the pressure fluid. The control slide has three positions, and would require a double stroke electromagnet, or two single-stroke electromagnets, so that a mechanical con trol device is provided.

SUMMARY OF THE INVENTION It is one object of the invention to overcome the disadvantages of control apparatus according to the prior art for controlling a plurality of hydraulic consumer motors, and to provide a control apparatus of simple and inexpensive construction, which takes up little space, and is suitable for use on mobile apparatus, such as harvesting machines.

Another object of the invention is to provide a hydraulic apparatus for the above-explained purpose in which the valves are spring-loaded into a first position, and are operated by single-stroke electromagnets to move into a second position against the action of the springs.

Another object of the invention is to provide a hydraulic control apparatus for the hydraulic motors of a harvesting machine which can be controlled from the dn'vers seat by operation of switches.

Another object of the invention is to control a plurality of hydraulic motors by electromagnetically operated valves in such a manner that by operation of switches, the hydraulic motors are capable of lifting, lowering, and holding loads.

With these objects in view, one embodiment of the invention comprises at least two consumer control means, preferably two abutting valve blocks and operation control means, preferably including a valve block abutting one of the valve plugs of the consumer control means.

Each consumer control means includes a pair of connecting conduits, a consumer conduit, and a consumer valve having biasing means for holding the consumer conduit from the connecting conduits, single-stroke electromagnets operatively connected with the consumer valve to move the same to an open position for connecting the connecting conduits with the consumer conduit. The pairs of connecting units of all consumer control means, and corresponding conduits in the operation control means, communicate with each other and form together connecting conduit means.

The operation control means include include inlet means for a pressure fluid and outlet means for fluid returned by the consumer apparatus, a control valve having biasing means for holding the control valve in a position for connecting the inlet means with the connecting conduit means and for disconnecting the same from the outlet means, and a single-stroke electromagnet operatively connected with the control valve for moving the same to a second position for connecting the outlet means with the connecting conduit means and for disconnecting the same from the inlet means whereby the flow of pressure fluid to consumers, and the return of fluid from the TUS FOR same can be individually and collectively controlled by the electromagnets of the consumer control means, and by the electromagnet of the operation control means.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a schematic sectional view illustrating a first embodiment of a control apparatus of the invention, and

FIG. 2 is a schematic sectional view illustrating a second embodiment of the control apparatus of the invention in which each consumer control means has two consumer conduits, and correspondingly two consumer valves.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to the embodiment of FIG. 1, two valve blocks 2 and 3, constituting consumer control means, are located between a valve block ll, constituting an operation control means, and an end plate 5.

The valve block 4 has an inlet 6, an outlet 7, a control valve 8, a return valve II), a pressure-limiting valve 11, and a check valve 12. Control valve 8 has a control valve slide I3 which is slidingly and sealingly guided in a cylinder bore 14 which has annular chambers l5, 16, 17 and 18 of which the innermost chamber I5 communicates with the return conduit and outlet 7. A conduit 20 connects chamber 17 with the surface 21 of the valve block 4, and chamber 18 is connected by an inlet conduit 22 with the inlet 6. Check valve I2 is located in conduit 22 and permits pressure relief from chamber 17. The small annular chamber 16 is connected by a conduit 23 to the surface 21 of valve block 4 which abuts surface 40 of valve block 2.

An annular groove divides control slide 13 into two piston portions 25, 26 which piston portion 25 closes chamber 16 in the illustrated position, while the annular groove connects chambers 17 and 118. A spring 27 is located in a recess of valve block 41 and abuts the end face of piston portion 25, while the other end of control valve slide 13 is operatively connected with the armature of a single-stroke control electromagnet 28, which is only schematically illustrated, and capable, when energized, to shift control valve slide 13 against the action of spring 27 to a second position.

Control valve slide I3 has axially extending pressure-compensating bores 30. Recess 31 in which spring 27 is located communicates through a control conduit 32 with the outlet and return conduit 7 which is connected to a container from which a schematically shown pump P provides pressure fluid into inlet 6.

Between the inlet and return conduits 6, 7, and control conduit portion 32, the pot-shaped return valve is located which includes a valve slide 34 and a spring 33 urging valve slide 34 to the illustrated position. The inner space 35 is connected by throttle bore 36 in the end plate of slide 34 with the inlet conduit 6 while another control conduit 37 connects the inner space 35 with the abutment face 21 of valve block 4. The pressure-limiting safety valve 11 is provided in a duct connecting the inlet conduit 6 with the return and outlet conduit 7.

The two valve blocks 2 and 3, which are respectively associated with different consumer apparatus, constitute consumer control means, and are of identical construction so that only valve block 2 will be described in detail. It will be understood that a greater number of consumer valve blocks can be provided if the number of consumer apparatus exceeds two.

Valve block 2 has parallel to the abutting surfaces 40 and 41 thereof a stepped blind bore 62, and a shoulder between the outer larger bore 43 and the inner smaller bore 44 forms a valve seat 45. The larger bore 43 is connected with a consumer conduit 46 which is connected with a schematically shown pipe 47 leading to a consumer apparatus, such as a piston and cylinder motor. The smaller bore 44 is penetrated by two connecting conduits 48, 50 of which the wider connecting conduit 48 communicates with conduit 20, and the narrower conduit 50 communicates with conduit 23 in valve block 4. The other end of conduits 50 and 48 communicate with corresponding conduits in valve block 3.

A valve slide 51 is mounted in the narrow bore 44 and has a piston end portion 52. Piston portion 51 is connected by a piston rod with a conical valve member 55 which has a piston rod 53 slidably guided, and sealed, in a plug 54. A conical valve body 55 is biased by a spring 56 to abut the valve seat 45. An annular groove between the piston portions of valve slide 51 connects two parts of connecting conduit 50 with each other. The end piston portion 52 forms a pressure chamber 58 which communicates through a conduit 60 with a control conduit 66. A parallel control conduit 65 includes an upstream portion 67 and a downstream portion 68. Conduits 67, 68 and 66 together with the corresponding conduits in valve block 3 are connected by an end conduit 75 in end plate 5, and communicate with conduits 37 and 32 in valve block 4, forming control conduit means.

The Shifiing piston 51 operates the consumer valve means 55, 54, 56 together with the actuating valve means 61 whose valve slide 63 is guided in a cylinder bore 64 which is penetrated by the control conduits 65 and 66. The upstream portion 67 of control conduit 65 is laterally staggered to the downstream conduit portion 68. Conduit 60 connects the pressure chamber 58 ofthe shifting piston 52 with the cylinder bore 64.

An annular groove 72 between two piston portions 70, 71 of the actuating valve means 61 connects in the illustrated position, which is determined by spring 69 and a stop, not shown, for the armature of consumer electromagnet 62. The annular groove 72 connects the conduit portions 67 and 68 of control conduit 65 with each other, and also connects conduit 60 with the return control conduit 66. Actuating valve slide 63 has longitudinal bores for pressure relief.

Conduits 37 and 32 in control valve block 4, conduits 65, 66 of both consumer valve blocks 2, 3, and end conduit 75 in end plate 7 form control conduit means 76 between the inlet 6 and the outlet 7.

The operation of the control apparatus is as follows: When the consumer electromagnet 62 of all consumer valve blocks 2 and 3, and the control electromagnet 28 of the control valve 8 are not energized, the respective slide valves 63 and 13 are in the illustrated positions of rest, in which pressure fluid, such as oil pumped by a pump, flows from inlet 6 and control conduit means 76 back into the outlet 7. The throttle bore 36 in the return valve causes a pressure differential between inlet 6 and control conduit 37 which displaces the return valve slide 34 against the action of spring 33 so that the inlet conduit 6 communicates with the outlet conduit 7, and the pump P idles. In these positions of the actuating valves 61 of the consumer valve blocks 2 and 3, the pressure chambers 58 are relieved into the outlet conduit 7 through control conduits 32, 66 and 60. Consequently, springs 56 of the consumer valves 55 of all consumer valve blocks 2 and 3 urge the valve members 55 to a closed position abutting seat 45, while lifting piston 51 is in the illustrated position. Consequently, a small pressure, as required for controlling return valve It), acts through check valve 12 and conduits and 23 and annular groove 24 of control valve slide 13, acts in connecting conduits 48 of the consumer valve blocks 2 and 3.

When consumer electromagnet 62 is energized and displaces its armature in a single stroke, actuating slide 63 is moved against the force of spring 69 to an actuating position in which the groove 72 connects only the conduit portion 67 of the control conduit means 76 with conduit 60 and pressure chamber 58. The circulation of pressure fluid is interrupted,

so that pressure builds up in control conduit 37 and return valve 10 closes and disconnects inlet conduit 6 from outlet conduit 7.

Pressure is built up in conduits 37 and 67 which are no longer relieved through conduits 66 and 32 into outlet conduit 7. The pressure in conduit 67 is transmitted through groove 72 and conduit 60 into pressure chamber 58 so that shifting piston 51, 52 is displaced and opens valve member 55 against the action of spring 56. In this position of valve member 55, connecting conduit 48 is connected with consumer conduit 46 so that pressure fluid from inlet conduit 6, flowing through conduits 22 and 20 into conduit 48 and consumer conduit 46, is supplied to the consumer apparatus connected by pipe 47 to consumer conduit 46.

When a consumer electromagnet 62 is deenergized by operation of a switch, not shown, spring 69 shifts actuating valve slide 63 to its position of rest. Pressure chamber 58 is relived of pressure, and spring 56 moves the consumer valve member 55 to the closed position abutting valve seat 45. The pressure fluid entering inlet conduit 6 displaces return valve 10 so that pressure fluid is discharged through the outlet conduit 7, and circulated by the pump P. However, by energization of consumer electromagnet 62 of the other consumer valve block 3, pressure fluid from inlet conduit 6 can be supplied through the connecting conduits to the consumer conduit 46 of the consumer valve block 3.

If the consumer electromagnet 62 of consumer valve block 2, and at the same time the control electromagnet of control valve 8 of the control valve block 4 are energized by a conventional circuit, not only actuating valve slide 63, but also control valve slide 13 are displaced out of the illustrated positions of rest.

The piston portion 26 of control valve slide 13 interrupts the communication between the annular chambers 17 and 18, and connects the annular chambers 15, 16 and l7 so that connecting conduit 48 of consumer valve block 2 communicates through conduit 20 with the outlet conduit 7.

At the same time, actuating valve slide 63 of actuating valve 61 is displaced, and the circulation of pressure fluid in control conduit means 76 is interrupted. The return valve 10 is at first closed, but the pressure building up in inlet conduit 6 acts in the pressure chamber 58 on shifting piston 51 and opens consumer valve member 55 so that consumer conduit 46 communicates with outlet conduit 7 and is relieved of pressure.

When consumer valve 45, 55 opens, end piston 52 of shifting piston 51 establishes communication between the pressure chamber 58 and conduit 50 which is connected by conduit 23 and chambers 15, 16 and with the outlet conduit 7. When pressure fluid flows along this path, return valve 10 opens and connects the inlet conduit 6 with the outlet conduit 7 until in inlet conduit 6 only the pressure required in pressure chamber 58 for holding the consumer valve 45, 55 open, prevails. in this manner, energy losses are held at a low level, and opening of consumer valve 45, 55 is assured. By simultaneously deenergizing the electromagnets 62 and 28, the flow of pressure fluid flowing from the consumer apparatus back into consumer conduit 46 can be stopped, whereupon the inlet conduit 6, as described above, is relieved by the return valve 10 into the outlet conduit 7, while consumer conduit 46 is closed by the spring-biased consumer valve member 55 abutting seat 45.

Consumer valve block 3 can be operated in the same manner as described for for consumer valve block 2 for controlling a hydraulic consumer apparatus to lift, hold, and lower a load in accordance with the electrical control of the consumer electromagnet 62 associated with consumer valve block 3.

The control apparatus is preferably designed so that only a single consumer valve block is operable at any time.

The embodiment of FIG. 2 corresponds substantially to the construction of FIG. 1, but provides two connecting conduits, two consumer valve means, and two consumer conduits in every valve block. Corresponding parts are indicated in FIGS. 1 and 2 by the same reference numerals.

The control valve means 81 is modified as compared with control valve means 8, and the cylinder bore 14 has, in addition to the chambers 15, 16, 17 and 18, two additional chambers @4 and 85. Chamber 64 has a conduit 87 opening on the abutment face 21 of control valve block 41, and communicating with a connecting conduit in consumer valve block 2. Chamber 85 is connected with a conduit 56 which opens into outlet conduit 7. Chamber 116 is placed adjacent the chamber 85, which does not change the function as explained with reference to MG. 1. Control valve slide has, in addition to the piston portions 25, 26, two additional piston portions 91, 92 which are formed by annular grooves 93, Ml. The annular groove 93 connects chambers 84, 85, while piston portions 91, 92 close chamber 16.

The consumer valve block 2' of the control apparatus 80 shown in MG. 2, and the identical consumer valve block 3', have the actuating valve means 61, the consumer valve means 51 with the shifting piston 52 and the conical valve member 55, the connecting conduit 48, and the consumer conduit 47, as the control apparatus 1 of FIG. 1. Additionally, each consumer valve block has a second connecting conduit 82, a second consumer valve means 96 with a conical valve member 98 and a shifting piston 109, and a second consumer conduit 97.

The shifting piston Wt) forms a pressure chamber 101 corresponding to, and connected by conduit 11112 with the pressure chamber 58 of the shifting piston 52. Due to the fact that two consumer valve means 55, 98 are provided, pistons 52 and 100 do not control a conduit corresponding to conduit 50 of the first embodiment, so that the annular grooves in shifting pistons 52 and wil omitted in the embodiment of FIG. 2.

The end plate 5 of the control apparatus 80 abuts the end face of the second consumer valve block 3, and if more consumer valve blocks are provided, on the last valve block so that the end conduit 75 connects the control conduits 65 with portions 67 and 68, and conduit 66. The entire control conduit means 76 is controlled by the return valve 10.

The control apparatus 80 shown in FlG. 2 operates substantially as the control apparatus 1 shown in H6. l with the following modification:

When the consumer electromagnet 62 and the control electromagnet 28 are not energized, the actuating valve means 61 and the control valve means 81 are in the illustrated positions in which the consumer conduits 47 and 97 are closed by the respective consumer valve members 55, 98 which abut the respective seats 45 due to the action of the respective springs. Consequently, a double-acting consumer apparatus such as a hydraulic cylinder and piston motor, and connected to the consumer conduits 47 and 97, is maintained in its position. The return valve 19 guides the pressure fluid from inlet conduit 6 directly into the outlet conduit 7 since the fluid can flow through the control conduit means 76.

When the control magnet 28 of the control valve means 81 is not energized, while the consumer electromagnet 62 of an actuating valve means 61 of one of the consumer valve blocks 2 or 3 is energized, the pressure in inlet conduit 6 builds pressure also in the pressure chambers 58 and 101, so that the first consumer valve means 51, 55, and also the second consumer valve means 96, 98 assume operative positions. Due to the fact that the control valve means 81 is still in the closed position, a first consumer conduit 67 is connected with the inlet conduit 6, and a second consumer conduit 97 is connected with the outlet conduit 7.

When the control magnet 62 of control valve means 81, and consumer electromagnet 62 of actuating valve means 61 are simultaneously energized, the conditions are reversed, and the first consumer conduit is connected through the consumer valve means 55, connecting conduit 43, 20 and chambers and 17 of control valve means 81, with the outlet conduit 7. The second consumer conduit 97 is connected with inlet conduit 6 through the second consumer valve means 98, connecting conduits 82, 87, and chambers 84 and 18 of control valve means 1 connection with conduit 22 which communicates with inlet conduit 6. By operation of the electromagnetic means, the piston of a double-acting hydraulic consumer motor can be driven in two opposite directions, and blocked in any intermediate position for lifting, lowering and holding a load.

The control apparatus of F161. 2 can be adapted for singleacting hydraulic consumer motors by additional consumer valve blocks. it is only necessary to add to the consumer valve blocks of the control apparatus 80, consumer valve blocks in which the connecting conduit 48, the control conduits 65 and 66, and the conduit 50 for the relief of the pressure chamber are positioned to match the position of the corresponding conduits in the adjacent consumer valve blocks. If an additional consumer valve block for a single-acting hydraulic consumer motor has a conduit corresponding to the second connecting conduit 82 of a consumer valve block 2' or 3, it is possible to stack consumer valve blocks for single-acting hydraulic consumer motors and for double-acting consumer motors in any sequence between the control valve block 4 and the end plate 5.

1n the embodiment of H65. 1 and 2, the consumer electromagnets 62 are operatively connected with the respective consumer valve means by actuating valve means 61 and shifting pistons 52 and 100. However, it is possible to directly connect the armature of the consumer electromagnet with the consumer valve member 55 or 98 for opening and closing the respective consumer conduit.

it will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of electrohydraulic control apparatus for consumer valves differing from the types described above.

While the invention has been illustrated and described as embodied in an apparatus including electromagnetic consumer valves in a plurality of consumer valve blocks, and a electromagnetic control valve in a control valve block, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

We claim:

1. Electrohydraulic control apparatus for consumer valves, comprising, in combination, at least two consumer control means, each including a connecting conduit, a consumer conduit means, and a consumer valve means having biasing means for holding said consumer valve means in a closed position disconnecting said consumer conduit means from said connecting conduits, single-stroke consumer electromagnetic means operatively connected with said consumer valve means to move the same to an open position for connecting said connecting conduits with said consumer conduit means; said connecting conduits of said consumer control means communicating with each other and forming together connecting conduit means; and operation control means including inlet means for a pressure fluid, and outlet means, control valve means having biasing means for holding said control valve means in a first position for connecting said inlet means with said connecting conduit means and for disconnecting the same from said outlet means, and single-stroke control electromagnetic means operatively connected with said control valve means for moving the same to a second position for connecting said outlet means with said connecting conduit means and for disconnecting the same from said inlet means whereby the flow of pressure fluid to consumers, and the return of fluid from the same can be controlled by said consumer and control electromagnetic means.

2. Control apparatus as claimed in claim 1, wherein each consumer valve means includes a biased valve member, and wherein said consumer electromagnetic means includes a movable spring-biased armature operatively connected with said valve member so that said consumer electromagnetic means, when energized, moves said valve member to said open position against the action of the respective biasing means.

3. Control apparatus as claimed in claim 1, wherein each consumer control means includes hydraulic actuating means for connecting said consumer electromagnetic means with said consumer valve means, said hydraulic actuating means including a cylinder, a shifting piston connected with said consumer valve means for moving the same to said open position, and forming a pressure chamber in said cylinder, and an actuating valve operated by said consumer electromagnetic means to connect said pressure chamber selectively with said inlet means and said outlet means.

4. Control apparatus as claimed in claim 3, comprising control conduit means connecting said inlet means and outlet means of said operation control means with all said consumer control means; and wherein said actuating valves of said consumer control means are located in said control conduit means.

5. Control apparatus as claimed in claim 4, wherein said actuating valve of each consumer control means includes a cylinder communicating with said control conduit means, an actuating valve slide in said cylinder, a spring biasing said actuating valve slide to a first position, said consumer electromagnetic means being connected with said actuating valve slide to move the same to a second position against the action of said spring, said actuating valve slide in said first position connecting said pressure chamber through said control conduit means with said outlet means, and connecting in said second position said pressure chamber through said control conduit means with said inlet means for moving said consumer valve means to said open position.

6. Control apparatus as claimed in claim 5, wherein said operation control means comprises return valve means between said inlet means and said outlet means and being spring-biased to a closed position disconnecting said inlet means from said outlet means, said return valve means having a throttle bore for connecting said inlet means with a portion of said control conduit means whereby a pressure differential is created for moving said return valve means to a position connecting said inlet means with said outlet means until one of said actuating valve means in said second position closes said portion of said control conduit means when the respective consumer electromagnetic means is energized.

7. Control apparatus as claimed in claim 3, wherein said consumer valve means of each consumer control means includes a biased valve member biased to said closed position,

and wherein said shifting piston is fixedly secured to said valve member and is moved by pressure in said pressure chamber to move said valve member to said open position, while connecting said consumer conduit means with said control valve means.

8. Control apparatus as claimed in claim 7, wherein said control valve means in said first position separates said pressure chamber from said outlet means, and connects said consumer conduit means with said outlet means if said control valve means is placed by said energized control electromagnetic means in said second position, and said consumer electromagnetic means is also energized so that pressure in said pressure chamber shifts said shifting piston to open said consumer valve means.

9. Control apparatus as claimed in claim 4, wherein each consumer control means includes a consumer valve block in which said actuating valve means, said shifting piston, portions of said connecting conduits and of said control conduit means, said pressure chamber, said consumer valve means and said consumer conduit are located, said consumer valve blocks abutting each other for connecting said portionsof said connectin conduit means and control conduit means.

l0. ontrol apparatus as claimed in claim 9, wherein said operation control means includes a control valve block abutting one of said consumer valve blocks of said consumer control means and including said outlet means, inlet means, control valve means and portions of said connecting conduit means and of said control conduit means.

11. Control apparatus as claimed in claim 10, comprising a block formed with an end conduit and abutting the other consumer valve block for connecting portions of said control conduit means therein by said end conduit.

12. Control apparatus as claimed in claim 9, wherein said consumer valve means include valve seat formed in the respective consumer valve block, and a spring-biased valve member engaging said seat in said ciosed position.

13. Control apparatus as claimed in claim 3, wherein each actuating valve slide is formed with a pressure-relieving passage therethrough; and wherein said control valve means include a biased control valve slide formed with a pressure-relieving passage therethrough, and being operated by said control electromagnetic means.

14. Control apparatus as claimed in claim 1, wherein each of said consumer control means includes two consumer conduits, and two connecting conduit means; wherein said control valve means include two valve portions controlling two conduits of said two connecting conduit means, respectively; and wherein each said consumer valve means includes two consumer valves respectively communicating with said two connecting conduit means and controlling said two consumer conduits; and two shifting pistons forming two interconnected pressure chambers. 

1. Electrohydraulic control apparatus for consumer valves, comprising, in combination, at least two consumer control means, each including a connecting conduit, a consumer conduit means, and a consumer valve means having biasing means for holding said consumer valve means in a closed position disconnecting said consumer conduit means from said connecting conduits, singlestroke consumer electromagnetic means operatively connected with said consumer valve means to move the same to an open position for connecting said connecting conduits with said consumer conduit means; said connecting conduits of said consumer control means communicating with each other and forming together connecting conduit means; and operation control means including inlet means for a pressure fluid, and outlet means, control valve means having biasing means for holding said control valve means in a first position for connecting said inlet means with said connecting conduit means and for disconnecting the same from said outlet means, and single-stroke control electromagnetic means operatively connected with said control valve means for moving the same to a second position for connecting said outlet means with said connecting conduit means and for disconnecting the same from said inlet means whereby the flow of pressure fluid to consumers, and the return of fluid from the same can be controlled by said consumer and control electromagnetic means.
 2. Control apparatus as claimed in claim 1, wherein each consumer valve means includes a biased valve member, and wherein said consumer electromagnetic means includes a movable spring-biased armature operatively connected with said valve member so that said consumer electromagnetic means, when energized, moves said valve member to said open position against the action of the respective biasing means.
 3. Control apparatus as claimed in claim 1, wherein each consumer control means includes hydraulic actuating means for connecting said consumer electromagnetic means with said consumer valve means, said hydraulic actuating means including a cylinder, a shifting piston connected with said consumer valve means for moving the same to said open position, and forming a pressure chamber in said cylinder, and an actuating valve operated by said consumer electromagnetic means to connect said pressure chamber selectively with said inlet means and said outlet means.
 4. Control apparatus as claimed in claim 3, comprising control conduit means connecting said inlet means and outlet means of said operation control means with all said consumer control means; and wherein said actuating valves of said consumer control means are located in said control conduit means.
 5. Control apparatus as claimed in claim 4, wherein said actuating valve of each consumer control means includes a cylinder communicating with said control conduit means, an actuating valve slide in said cylinder, a spring biasing said actuating valve slide to a first position, said consumer electromagnetic means being connected with said actuating valve slide to move the same to a second position against the action of said spring, said actuating valve slide in said first position connecting said pressure chamber through said control conduit means with said outlet means, and connecting in said second position said pressure chamber through said control conduit means with said inlet means for moving said consumer valve means to said open position.
 6. Control apparatus as claimed in claim 5, wherein said operation control means comprises return valve means between said inlet means and said outlet means and being spring-biased to a closed position disconnecting said inlet means from said outlet means, said return valve means having a throttle bore for connecting said inlet means with a portion of said control conduit means whereby a pressure differential is created for moving said return valve means to a position connecting said inlet means with said outlet means until one of said actuating valve means in said second position closes said portion of said control conduit means when the respective consumer electromagnetic means is energized.
 7. Control apparatus as claimed in claim 3, wherein said consumer valve means of each consumer control means includes a biased valve member biased to said closed position, and wherein said shifting piston is fixedly secured to said valve member and is moved by pressure in said pressure chamber to move said valve member to said open position, while connecting said consumer conduit means with said control valve means.
 8. Control apparatus as claimed in claim 7, wherein said control valve means in said first position separates said pressure chamber from said outlet means, and connects said consumer conduit means with said outlet means if said control valve means is placed by said energized control electromagnetic means in said second position, and said consumer electromagnetic means is also energized so that pressure in said pressure chamber shifts said shifting piston to open said consumer valve means.
 9. Control apparatus as claimed in claim 4, wherein each consumer control means includes a consumer valve block in which said actuating valve means, said shifting piston, portions of said connecting conduits and of said control conduit means, said pressure chamber, said consumer valve means and said consumer conduit are located, said consumer valve blocks abutting each other for connecting said portions of said connecting conduit means and control conduit means.
 10. Control apparatus as claimed in claim 9, wherein said operation control means includes a control valve block abutting one of said consumer valve blocks of said consumer control means and including said outlet means, inlet means, control valve means and portions of said connecting conduit means and of said control conduit means.
 11. Control apparatus as claimed in claim 10, comprising a block formed with an end conduit and abutting the other consumer valve block for connecting portions of said control conduit means therein by said end conduit.
 12. Control apparatus as claimed in claim 9, wherein said consumer valve means include valve seat formed in the respective consumer valve block, and a spring-biased valve member engaging said seat in said closed position.
 13. Control apparatus as claimed in claim 3, wherein each actuating valve slide is formed with a pressure-relieving passage therethrough; and wherein said control valve means include a biased control valve slide formed with a pressure-relieving passage therethrough, and being operated by said control electromagnetic means.
 14. Control apparatus as claimed in claim 1, wherein each of said consumer control means includes two consumer conduits, and two connecting conduit means; wherein said control valve means include two valve portions controlling two conduits of said two connecting conduit means, respectively; and wherein each said consumer valve means includes two consumer valves respectively communicating with said two connecting conduit means and controlling said two consumer conduits; and two shifting pistons forming two interconnected pressure chambers. 